Ignatius Insight: Your most recent novel, A Cry of Stone, is the fifth book in the Children of the Last Days series. What was the inspiration and idea behind this series of novels?

O’Brien: It began one day in the mid-1990’s, when I was visiting the Blessed Sacrament in my local parish. I was praying for the Church. Suddenly overwhelmed by the reality of how many particular Catholic churches in the Western world have been seduced by materialism and have slid into grave sin and error, I was stricken with a deep grief. Though I am not an especially emotional person by nature, I began to weep….a profound weeping and groaning that was more spiritual than emotional. I begged God to purify and strengthen the Church in my land, in all the Americas and Western Europe.